Visual detection of LAMP products for the detection of serotype 1 MDV. SYBR green I dye (1:1,000) (2 μl) was added to all the tubes after termination of the LAMP reaction. LAMP-positive reactions turned to apple green, while negative reactions remained brown. Tube 1, DNA from Ind/KA01/06 serotype 1 MDV isolate; tube 2, DNA from serotype 2 SB-1 vaccine; tube 3, DNA from serotype 3 HVT vaccine; tube 4, DNA from healthy chicken feather.